improve code quality

grpc.go

@@ -339,7 +339,9 @@ func (g *grpcClient) Call(ctx context.Context, req client.Request, rsp interface
 	d, ok := ctx.Deadline()
 	if !ok {
 		// no deadline so we create a new one
-		ctx, _ = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, callOpts.RequestTimeout)
+		defer cancel()
 	} else {
 		// got a deadline so no need to setup context
 		// but we need to set the timeout we pass along